  - update to 5.2.1
  - explain and clean up the bdb stuff in lang/ocaml
  - sort PLISTs consistently between lang/ocaml and this, to enable
    understanding what is changed
  - create COMMIT_MESSAGE
    + explain why *all* the patches in lang/ocaml are missing
    + explain PLIST changes
    + explain why pic and flambda options are being removed
  - create meta-pkgs/bulk-test-ocaml and test
  - examine unresolved upstream 5.x issues
    + https://github.com/ocaml/ocaml/issues/11913
    + https://github.com/ocaml/ocaml/issues/13262
    + https://github.com/ocaml/ocaml/pull/13320
    in light of the prominent caution at
      https://github.com/ocaml/ocaml/blob/trunk/README.adoc
    - run tests and assess
